MALDI-TOF MS IN BLOOD STREAM INFECTION
Dr.T.V.Rao MD
A TOPIC FOR POST GRADUATES IN LABORATORY MEDICINE
Question – Why we need to use newer methods in diagnosis of septicemia and write a note on MALDI-TOF MS? With advances In Technology the Microbiologists should walk to future, with technology, , The study of microbiology is undergoing a renaissance owing to the development and application of a diverse range of new technologies, Soon the matters we are all well versed in traditional microbiology will be obsolete in critical care of the patients, Increasingly sophisticated sequencing approaches, coupled with improved analytical and computational tools, allow us to rapidly identify pathogens, track infectious disease outbreaks and identify links between microorganisms and disease. Rapid identification of microorganisms in the clinical microbiology laboratory can be of great value for selection of optimal patient management strategies for infections caused by bacteria, viruses, fungi, mycobacteria, and parasites. Rapid identification of microorganisms in clinical samples enables expedient de-escalation from broad-spectrum agents to targeted antimicrobial therapy We certainly need the revamp in critical conditions as septic shock where every minute to life counts, Rapid identification of BSIs and the associated condition known as sepsis syndrome are of importance because of associated morbidity and mortality. Despite the evidence showing that the rapid administration of an effective antibiotic saves lives tools in clinical microbiology are primarily based on techniques that evolved 30 to 40 years ago, We certainly receive at least double digit numbers of blood for culturing, I am certain 5- 10% of the specimens get contaminant, majority are sterile even after 1 week of incubation, leading to greater disappointment of clinicians who unfortunately depended on Microbiology in the last hour of crisis . The automated BacT/ALERT® 3D system allows rapid bacterial detection of positive blood cultures in cases of septicemia. however, there is an urgent need for new technologies in microbiology to circumvent the issue of lag time for reports from positive blood cultures and other cultures. Sepsis, a common sequela of BSIs, ranks among the top 10 causes of death in the United States, where over 600 patients die each day. We have no proper statistics. According to the literature, the risk of death from septic shock increases by over 7% with every hour that passes from the onset of shock until the start of targeted therapy. Several other studies confirm the urgency of rapid identification of pathogens and its benefit to survival and costs and the effective targeting of antimicrobial therapy, Unfortunately, when laboratory methods rely solely on cultivation of pathogens and traditional phenotypic methods of pathogen characterization, physicians are forced to deduce the presence of BSI based on clinical symptoms, which are often nonspecific. Subsequently, antibiotic therapy is initiated based on clinical and epidemiological profiles rather than on laboratory evidence. Typically, within 1 to 3 days a microscopic Gram stain category (Gram-positive bacteria, Gram-negative bacteria, or fungi) provides physicians with a general direction for antibiotic therapy. I always insisted observation of gram stain is priority whenever you find little of turbidity in culture bottles in resource poor laboratories. if we can identify whether it is a gram positive or negative gives a greater idea in choosing the Antibiotics, However the world is going to newer technologies in all BSI (Blood stream Infections) which carry higher mortality. Much of the western hospitals are taking the advantage new technologies as priority much newer to the world is MALDI-TOF MS. The advent of MALDI-TOF Mass Spectrometry for the rapid ID of pathogens was a breakthrough in microbiology. Recently, this method was combined with extraction methods for pathogens directly from positive blood cultures recently it is widely used because of its high accuracy, low consumable cost, and speed of analysis. It is estimated that MALDI-TOF MS requires about 105 of colony forming units (cfu) to have an enough bacterial ribosomal protein to obtain a reliable protein pattern, which is specific for a certain pathogen. A typical experiment consists of outgrowth of bacteria, colony selection and placement on a target, addition of matrix, and analysis with MALDI-TOF MS. Mass spectrometry identification is broadband such that the method can measure multiple analyses simultaneously, does not require prior knowledge about the organism, and is both fast and sensitive in that it does not require a prefabrication step. It generally measures all m/z between 2 and 20 kDa. Several reviews are available on this topic for a more in-depth overview, by cost, complexity, and throughput, many of the newly developed technologies will only be affordable for large reference or university-based diagnostic laboratories. The working group strongly urges the development of platforms that could have utility for hospitals, regardless of their size. In a country like India it is not possible start a MALDI-TOF MS in individual laboratories, we can certainly to have pooled system of laboratories and the samples can be sent to the available laboratory for care of critically ill patients in Sepsis.
HOWEVER, IT IS A GREAT PRIORITY TO MOVE FROM TRADITIONAL TO TECHNOLOGICAL ADVANCES OR ELSE THE LIFE IN CRISIS IN CRITICAL CARE SETTINGS
Ref New Technologies in Clinical Microbiology Donna M. Wolk1,* and W. Michael Dunne Jr. journal of Clinical Microbiology J. Clin. Microbiol. September 2011 vol. 49 no. 9 Supplement S62-S6
Created for on line resources on INFECTIOUS DIESEASES
Dr.T.V.Rao MD Freelance Reporter on Infectious diseases
Dr.T.V.Rao MD
A TOPIC FOR POST GRADUATES IN LABORATORY MEDICINE
Question – Why we need to use newer methods in diagnosis of septicemia and write a note on MALDI-TOF MS? With advances In Technology the Microbiologists should walk to future, with technology, , The study of microbiology is undergoing a renaissance owing to the development and application of a diverse range of new technologies, Soon the matters we are all well versed in traditional microbiology will be obsolete in critical care of the patients, Increasingly sophisticated sequencing approaches, coupled with improved analytical and computational tools, allow us to rapidly identify pathogens, track infectious disease outbreaks and identify links between microorganisms and disease. Rapid identification of microorganisms in the clinical microbiology laboratory can be of great value for selection of optimal patient management strategies for infections caused by bacteria, viruses, fungi, mycobacteria, and parasites. Rapid identification of microorganisms in clinical samples enables expedient de-escalation from broad-spectrum agents to targeted antimicrobial therapy We certainly need the revamp in critical conditions as septic shock where every minute to life counts, Rapid identification of BSIs and the associated condition known as sepsis syndrome are of importance because of associated morbidity and mortality. Despite the evidence showing that the rapid administration of an effective antibiotic saves lives tools in clinical microbiology are primarily based on techniques that evolved 30 to 40 years ago, We certainly receive at least double digit numbers of blood for culturing, I am certain 5- 10% of the specimens get contaminant, majority are sterile even after 1 week of incubation, leading to greater disappointment of clinicians who unfortunately depended on Microbiology in the last hour of crisis . The automated BacT/ALERT® 3D system allows rapid bacterial detection of positive blood cultures in cases of septicemia. however, there is an urgent need for new technologies in microbiology to circumvent the issue of lag time for reports from positive blood cultures and other cultures. Sepsis, a common sequela of BSIs, ranks among the top 10 causes of death in the United States, where over 600 patients die each day. We have no proper statistics. According to the literature, the risk of death from septic shock increases by over 7% with every hour that passes from the onset of shock until the start of targeted therapy. Several other studies confirm the urgency of rapid identification of pathogens and its benefit to survival and costs and the effective targeting of antimicrobial therapy, Unfortunately, when laboratory methods rely solely on cultivation of pathogens and traditional phenotypic methods of pathogen characterization, physicians are forced to deduce the presence of BSI based on clinical symptoms, which are often nonspecific. Subsequently, antibiotic therapy is initiated based on clinical and epidemiological profiles rather than on laboratory evidence. Typically, within 1 to 3 days a microscopic Gram stain category (Gram-positive bacteria, Gram-negative bacteria, or fungi) provides physicians with a general direction for antibiotic therapy. I always insisted observation of gram stain is priority whenever you find little of turbidity in culture bottles in resource poor laboratories. if we can identify whether it is a gram positive or negative gives a greater idea in choosing the Antibiotics, However the world is going to newer technologies in all BSI (Blood stream Infections) which carry higher mortality. Much of the western hospitals are taking the advantage new technologies as priority much newer to the world is MALDI-TOF MS. The advent of MALDI-TOF Mass Spectrometry for the rapid ID of pathogens was a breakthrough in microbiology. Recently, this method was combined with extraction methods for pathogens directly from positive blood cultures recently it is widely used because of its high accuracy, low consumable cost, and speed of analysis. It is estimated that MALDI-TOF MS requires about 105 of colony forming units (cfu) to have an enough bacterial ribosomal protein to obtain a reliable protein pattern, which is specific for a certain pathogen. A typical experiment consists of outgrowth of bacteria, colony selection and placement on a target, addition of matrix, and analysis with MALDI-TOF MS. Mass spectrometry identification is broadband such that the method can measure multiple analyses simultaneously, does not require prior knowledge about the organism, and is both fast and sensitive in that it does not require a prefabrication step. It generally measures all m/z between 2 and 20 kDa. Several reviews are available on this topic for a more in-depth overview, by cost, complexity, and throughput, many of the newly developed technologies will only be affordable for large reference or university-based diagnostic laboratories. The working group strongly urges the development of platforms that could have utility for hospitals, regardless of their size. In a country like India it is not possible start a MALDI-TOF MS in individual laboratories, we can certainly to have pooled system of laboratories and the samples can be sent to the available laboratory for care of critically ill patients in Sepsis.
HOWEVER, IT IS A GREAT PRIORITY TO MOVE FROM TRADITIONAL TO TECHNOLOGICAL ADVANCES OR ELSE THE LIFE IN CRISIS IN CRITICAL CARE SETTINGS
Ref New Technologies in Clinical Microbiology Donna M. Wolk1,* and W. Michael Dunne Jr. journal of Clinical Microbiology J. Clin. Microbiol. September 2011 vol. 49 no. 9 Supplement S62-S6
Created for on line resources on INFECTIOUS DIESEASES
Dr.T.V.Rao MD Freelance Reporter on Infectious diseases
thanks for the info
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